This Annual Report on Form 10-K (“Form 10-K”) is being filed by Federal Signal Corporation and its subsidiaries (referred to collectively as the “Company,” “we,” “our” or “us” herein, unless the context otherwise indicates) with the United States (“U.S.”) Securities and Exchange Commission (the “SEC”), and includes comments made by management that may contain words such as “may,” “will,” “believe,” “expect,” “anticipate,” “intend,” “plan,” “project,” “estimate” and “objective” or similar terminology, or the negative thereof, concerning the Company’s future financial performance, business strategy, plans, goals and objectives. These expressions are intended to identify forward-looking statements within the meaning of Section 27A of the Securities Act of 1933, as amended (the “Securities Act”), Section 21E of the Securities Exchange Act of 1934, as amended (the “Exchange Act”) and the Private Securities Litigation Reform Act of 1995. Forward-looking statements include information concerning the Company’s possible or assumed future performance or results of operations and are not guarantees. While these statements are based on assumptions and judgments that management has made in light of industry experience as well as perceptions of historical trends, current conditions, expected future developments and other factors believed to be appropriate under the circumstances, they are subject to risks, uncertainties and other factors that may cause the Company’s actual results, performance or achievements to be materially different.

Federal Signal Corporation, founded in 1901, was reincorporated as a Delaware corporation in 1969. The Company designs and manufactures a suite of products and integrated solutions for municipal, governmental, industrial and commercial customers. The Company’s portfolio of products includes sewer cleaners, vacuum trucks, street sweepers, waterblasters, safety and security systems, including technology-based products and solutions for the public safety market, and vehicle-mounted aerial platforms.market. In addition, we sell parts and provide service, repair, equipment rentals and training as part of a comprehensive offering to our customers. Federal Signal Corporation and its subsidiaries operate twelvenine principal manufacturing facilities in sixfour countries around the world and provide products and integrated solutions to customers in all regions of the world.

Products manufactured and services rendered by the Company are divided into threetwo major operating segments: the Environmental Solutions Group and the Safety and Security Systems Group and the Fire Rescue Group. The individual operating businesses are organized as such because they share certain characteristics, including technology, marketing, distribution and product application, which create long-term synergies. Corporate contains those items that are not included in our operating segments.

The Environmental Solutions and Fire Rescue groups useGroup uses either a dealer networks andnetwork or direct sales to service customers generally depending on the type and geographic location of the customer. The Environmental Solutions Group’s direct sales channel concentrates on the industrial, utility and construction market segments, while the dealer networks focusnetwork focuses primarily on the municipal markets.market. Dealer representatives demonstrate the vehicles’ functionalities and capabilities to customers and service the vehicles on a timely basis. The Company believes its national and global dealer networks for vehicles distinguishesdistinguish it from its competitors.

Total orders in 20142015 were $957.4$686.1 million, of which approximately 38%47% were to U.S. municipal and governmental customers, 29%26% were to U.S. commercial and industrial customers and 33%27% were to non-U.S. customers. No single customer accounted for 10% or more of the Company’s business.

The Company purchases a wide variety of raw materials from around the world for use in the manufacture of its products, although the majority of current purchases are from North American sources. To minimize risks relating to availability, price and quality of key products and components, the Company is party to numerous strategic supplier arrangements. Although certain materials are obtained from either a single-source supplier or a limited number of suppliers, the Company has generally identified alternative sources to minimize the interruption of its business in the event of supply problems.disruptions.

Within the Environmental Solutions Group, Elgin is recognized as a market leader among several domestic sweeper competitors and differentiates itself primarily on product performance. The Vactor and Guzzler bothbrands each maintain a leading domestic position in their respective marketplaces by enhancing product performance with leading technology and application flexibility. Jetstream is a market leader in the in-plant cleaning segment of the U.S. waterblast industry, competing on product performance, rapid delivery and rapid delivery.solutions services.

The Company invests in research to support the development of new products and the enhancement of existing products and services. The Company believes this investment is important to maintain and/or enhance its leadership position in key markets. Expenditures for research and development by the Company were $16.6$14.0 million in 2015, $13.1 million in 2014 and $11.0 million in 2013, and $10.0 million in 2012, and were reported within selling,Selling, engineering, general and administrative expenses.(“SEG&A”) expenses on the Consolidated Statement of Operations.

The Company employed approximately 2,7002,200 people in its businesses at December 31, 20142015 with the Company’s U.S. hourly workers accounting for approximately 42%48% of its total workforce. Approximately 24% of the Company’s U.S. hourly workers were represented by unions at December 31, 2014.2015. We believe that our labor relations with our employees are good.

The Company believes it substantially complies with federal, state and local provisions that have been enacted or adopted regulating the discharge of materials into the environment, or otherwise relating to the protection of the environment. Capital expenditures in 20142015 attributable to compliance with such laws were not material. The Company believes that the overall impact of compliance with environmental regulations will not have a material adverse effect on our financial position, results of operations or cash flow.

Certain of the Company businesses are susceptible to the influences of seasonal buying or delivery patterns. The Company tends to have lower sales in the first quarter compared to other quarters as a result of these influences.

The following is a list of the Company’s executive officers, their ages, business experience and positions as of February 1, 2015:15, 2016:

We may occasionally make forward-looking statements and estimates such as forecasts and projections of our future performance or statements of our plans and objectives. These forward-looking statements may be contained in, but are not limited to, filings with the SEC, including this Form 10-K, press releases made by us and oral statements made by our officers. Actual results could differ materially from those contained in such forward-looking statements. Important factors that could cause our actual results to differ from those contained in such forward-looking statements include, but are not limited to, the risks described below.

In 2014,2015, we generated approximately 65%75% of our net sales in the U.S. Our ability to be profitable depends heavily on varying conditions in the U.S. governmental and municipal markets, as well as the overall U.S. economy. The industrial markets in which we compete are subject to considerable cyclicality, and move in response to cycles in the overall business environment. Many of our customers are municipal government agencies, and as a result, we are dependent on municipal government spending. Spending by our municipal customers can be affected by local political circumstances, budgetary constraints and other factors. The U.S. government and municipalities depend heavily on tax revenues as a source of spending and accordingly, there is a historical correlation that suggests a lag of a one or two-year lagtwo years between the condition of the U.S. economy and our sales to the U.S. government and municipalities. Therefore, downturns in the U.S. economy are likely to result in decreases in demand for our products. During previous economic downturns, we experienced decreases in sales and profitability, and we expect our business to remain subject to similar economic fluctuations in the future.

Our business is subject to fluctuations in demand and changing international economic, legal and political conditions that are beyond our control. In 2014,2015, approximately 35%25% of our net sales were generatedto customers outside the U.S. and we expect a significant portion of our revenues to come from international sales in the foreseeable future. Operating in the international marketplace exposes us to a number of risks, including the need to comply with U.S. and foreign laws and regulations applicable to our foreign operations, such as the Foreign Corrupt Practices Act, (the “FCPA”), the United Kingdom (“U.K.”) Bribery Act and their counterparts in other foreign jurisdictions in which we operate, restrictive domestic and international trade regulations, including the imposition of tariffs and trade barriers on our products, changes in these laws, regulations and policies by the U.S. and foreign governments, political and economic instability in the jurisdictions in which we operate, foreign receivables collection risk, local labor market conditions, and, in some cases, international hostilities. The costs of compliance with these various laws, regulations and policies can be significant and penalties for non-compliance could significantly impact our business.

Economic downturns result in tighter credit markets, which could adversely affect our customers’ ability to secure financing or to secure financing at favorable terms or interest rates necessary to proceed or continue with purchases of our products and

services. Our customers’ or potential customers’ inability to secure financing for projects could result in the delay, cancellation or downsizing of new purchases or the suspension of purchases already under contract, which could cause a decline in the demand for our products and services and negatively impact our financial position, results of operations or cash flow.

We place a high priority on developing new products and services, as well as enhancing our existing products and services. As a result of these efforts, we may be required to expend substantial research, development and marketing resources, and the time and expense required to develop a new product or service or enhance an existing product or service are difficult to predict. We may not succeed in developing, introducing or marketing new products or services or product or service enhancements. In addition, we cannot be certain that any new or enhanced product or service will generate sufficient revenue to justify the expense and resources devoted to this product diversification effort.

We continue to evaluate opportunities to restructure our business and rationalize our manufacturing operations in an effort to optimize our cost structure. These actions could result in significant charges that could adversely affect our financial condition and results of operations. Future actions could result in restructuring and related charges, including but not limited to impairments, employee termination costs and charges for pension and other postretirement contractual benefits and pension curtailments that could be significant and could have an adverse effect on our financial condition, results of operations or cash flow.

The markets in which we operate are highly competitive. Many of our competitors have significantly greater financial resources than we do. The intensity of this competition, which is expected to continue, can result in price discounting and margin pressures throughout the industry and may adversely affect our ability to increase or maintain prices for our products. In addition, certain of our competitors may have lower overall labor or material costs. In some cases, our contracts with municipal and other governmental customers are awarded and renewed through competitive bidding. We may not be successful in obtaining or renewing these contracts, which could have an adverse effect on our financial condition, results of operations or cash flow.

We are exposed to product liability and warranty claims in the normal course of business in the event that our products actually or allegedly fail to perform as expected, or the use of our products results, or is alleged to result, in bodily injury and/or property damage. For example, we have been sued by firefighters seeking damages claiming that exposure to our sirens has impaired their hearing and that the sirens are, therefore, defective. In addition, we are subject to other claims and litigation from time to time as further described in the accompanying notes to our consolidated financial statements. We could experience material warranty or product liability costs in the future and incur significant costs to defend ourselves against these claims. While we carry insurance and maintain reserves for product liability claims, our insurance coverage may be inadequate if such claims do arise, and any defense costs and liability not covered by insurance could have a material adverse impact on our financial condition, results of operations or cash flow. A future claim could involve the imposition of punitive damages, the award of which, pursuant to state laws, may not be covered by insurance. In addition, warranty and certain other claims are not typically covered by insurance. Any product liability or warranty issues may adversely impact our reputation as a manufacturer of high quality, safe products and may have a material adverse effect on our business.

We are engaged in an industry that will be affected by future technological developments. The introduction of products or processes utilizing new technologies could render our existing products or processes obsolete or unmarketable. Our success will depend upon our ability to develop and introduce on a timely and cost-effective basis new products, applications and processes that keep pace with technological developments and address increasingly sophisticated customer requirements. We may not be successful in identifying, developing and marketing new products, applications and processes and product or process enhancements. We may experience difficulties that could delay or prevent the successful development, introduction and marketing of product or process enhancements or new products, applications or processes. Our products, applications or processes may not adequately meet the requirements of the marketplace and achieve market acceptance. Our financial

condition, results of operations or cash flow could be materially and adversely affected if we were to incur delays in developing new products, applications or processes or product or process enhancements, or if our products do not gain market acceptance.

We purchase from suppliers raw materials and component parts to be used in the manufacturing of our products. In addition, we purchase certain finished goods from suppliers. Changes in our relationships with suppliers, shortages, production delays, regulatory restrictions or work stoppages by the employees of such suppliers could have a material adverse effect on our ability to timely manufacture and market products. In addition, increases in the costs of purchased raw materials, component parts or finished goods could result in manufacturing interruptions, delays, inefficiencies or our inability to market products. In addition, our profit margins would decrease if prices of purchased raw materials, component parts or finished goods increase and we are unable to pass on those increases to our customers.

Our ability to operate our businesses and implement our strategies depends in part on the efforts of our executive officers and other key employees. In addition, our future success will depend on, among other factors, our ability to attract and retain qualified personnel, including finance personnel, research professionals, technical sales professionals and engineers. The loss of the services of any key employee or the failure to attract or retain other qualified personnel could have a material adverse effect on our business or business prospects.

We rely on a national and global dealer networknetworks to market certain of our products and services. A disruption in our dealer network, or with a significant dealer, or within a specific market, could have an adverse impact on our business within the affected market. In addition, our dealers require adequate liquidity to finance their operations, including purchases of our products.  Dealers are subject to numerous risks and uncertainties that could unfavorably affect their liquidity positions, including, among other things, continued access to adequate financing sources on a timely basis on reasonable terms.  These sources of financing are vital to our ability to sell products through our dealer network. Deterioration in the liquidity or credit worthiness of our dealers could have a significant adverse effect on our business and could, in some limited cases, trigger repurchase obligations under an existing agreement with a third-party finance company that provides financing to certain of our dealers to support the purchase of our products. The loss or termination of a significant dealer, or a significant number of dealers, could cause difficulties in marketing and distributing our products and have an adverse effect on our business, financial condition, results of operations or cash flow.

We are subject to risk of work stoppages and other labor relations matters because a portion of our workforce is unionized. As of December 31, 2014,2015, approximately 24% of our U.S. hourly workers were represented by labor unions and were covered by collective bargaining agreements. Many of these agreements include provisions that limit our ability to realize cost savings. Our current collective bargaining agreement with the International Brotherhood of Electrical Workers is due to expire in April 2016. Any strikes, threats of strikes or other organized disruptions in connection with the negotiation of new labor agreements or other negotiations could materially adversely affect our business as well as impair our ability to implement further measures to reduce costs and improve production efficiencies.

Our funding obligations and pension expense for our defined benefit pension plans are driven by the performance of assets set aside in trusts for these plans, the discount rate used to value the plans’ liabilities, actuarial assumptions and experience and legal and regulatory funding requirements. Changes in these factors could have an adverse impact on our financial condition, results of operations or cash flow. In addition, a portion of our pension plan assets are invested in equity securities, which can experience significant declines if financial markets weaken. The level of the funding of our defined benefit pension plan liabilities was approximately 77%79% as of December 31, 2014.2015. The current year funding status was impacted by lowerhigher discount rates and revised mortality assumptions which project longer life expectancy.rates. Our future pension expenses and funding requirements could increase significantly due to the effect of adverse changes in the discount rate, asset values or the estimated expected return on plan assets. In addition, we could be legally required to make increased cash contributions to the pension plans, and these contributions could be material and negatively affect our cash flow.

We, like other manufacturers, continue to face heavy governmental regulation of our products, especially in the areas of the environment and employee health and safety. Complying with environmental and safety requirements has added and will continue to add to the cost of our products, and could increase the capital required to support our business. While we believe that we are in compliance in all material respects with these laws and regulations, we may be adversely impacted by costs, liabilities or claims with respect to our operations under existing laws or those that may be adopted. These requirements are complex, change frequently and have tended to become more stringent over time. Therefore, we could incur substantial costs, including cleanup costs, fines and civil or criminal sanctions as a result of violation of, or liabilities under, environmental laws and safety regulations. These requirements may increase the cost of our products, which may diminish demand for those products. In addition, uneven application of environmental or safety regulations could place our products at a cost or features disadvantage, which could reduce our revenues and profitability.

Presently, the only U.S. federal net operating loss carryforwards (“NOLs”) we have remaining are from previously acquired companies and hence are limited to specific annual amounts as permitted by Section 382 of the Internal Revenue Code of 1986, as amended (“Section 382”). If an ownership change, as defined in Section 382, occurs with respect to our capital stock, our ability to use these NOLs could be further limited to more restrictive specific annual amounts. Generally, an ownership change occurs if certain persons or groups increase their aggregate ownership by more than 50% of our total capital stock in a three-year period. If more than a 50% ownership change were to occur, use of our NOLs to reduce payments of federal tax may be deferred to later years within the 20-year carryover period; however, if the carryover period for any loss year expires, the use of the remaining NOLs for the loss year will be prohibited. If we should fail to generate a sufficient level of taxable income prior to the expiration of the applicable NOL carryforward periods, then we will lose the ability to apply the NOLs as offsets to future taxable income. We also have a significant amount of tax credit carryforwards (“tax credits”) which are generally available to offset future U.S. income tax. The usage of these tax credits is subject to similar limitations upon a change in ownership. AtAs of December 31, 2014,2015, our tax credits totaled $30.8$13.1 million and had various carryforward periods, generally ranging from 3with the majority beginning to 20expire in approximately six years.

We have a substantial amount of goodwill, which is recorded at fair value at the time of acquisition and is not amortized, but is reviewed for impairment at least annually or more frequently if impairment indicators arise. In evaluating the potential for impairment of goodwill, we make assumptions regarding future operating performance, business trends, competition and market and general economic conditions. Such analyses further require us to make certain assumptions about our sales, operating margins, growth rates and discount rates. There are inherent uncertainties related to these factors and in applying

these factors to the assessment of goodwill recoverability. Goodwill reviews are prepared using estimates of the fair value of reporting units, which incorporate estimates of the present value of future discounted cash flow. We could be required to evaluate the recoverability of goodwill prior to the annual assessment if we experience disruptions to the business, unexpected significant declines in operating results, a divestiture of a significant component of our business or our market capitalization declines.

Our long-term strategy includes exploring acquisition of companies or businesses to facilitate our growth, enhance our global market position and broaden our product offerings. Such acquisitions may help us expand into adjacent markets, add complementary products and services or allow us to leverage our distribution channels. In connection with this strategy, we could face certain risks and uncertainties in addition to those we face in the day-to-day operations of our business. We also may be unable to identify suitable targets for acquisition or to make acquisitions at favorable prices. If we identify a suitable acquisition candidate, our ability to successfully implement the acquisition would depend on a variety of factors, including our ability to obtain financing on acceptable terms. In addition, our acquisition activities could be disrupted by overtures from competitors for the targeted companies, governmental regulation and rapid developments in our industry that decrease the value of a potential target’s products or services.

We may assume liabilities in connection with the acquisition of businesses. There may be liabilities that we fail or are unable to discover in the course of performing due diligence investigations on the acquired businesses.businesses, or that may be more material than we discovered. In these circumstances, we cannot assure that our rights to indemnification from the sellers of the acquired businesses to us will be sufficient in amount, scope or duration to fully offset the possible liabilities associated with the businesses or property acquired. Any such liabilities, individually or in the aggregate, could have a material adverse effect on our financial condition, results of operations or cash flow.

None.

As of December 31, 2014,2015, the Company utilized six principal manufacturing plants located throughout the U.S., as well as fivetwo in Europe and one in South Africa. The Company also leases certain facilities within the U.S. and Europe from which we sell parts and/or provide service. As of December 31, 2014,2015, the Company devoted approximately 1.00.9 million square feet to manufacturing and 0.60.5 million square feet to service, warehousing and office space. Of the total square footage, approximately 46%56% is devoted to the Environmental Solutions Group 39%and 44% to the Safety and Security Systems Group and 15% to the Fire Rescue Group. Approximately 21%19% of the total square footage is owned by the Company with the remaining 79%81% being leased. Owned facilities are subject to lien under the Company’s Senior SecuredAmended and Restated Credit FacilityAgreement dated March 13, 2013January 27, 2016 (the “Senior Secured“2016 Credit Facility”Agreement”).

The information concerning the Company’s legal proceedings included in Note 9 – Legal Proceedings to the accompanying consolidated financial statements is incorporated herein by reference.

Not applicable.

As of February 28, 2015,January 31, 2016, there were 1,8461,753 holders of record of the Company’s common stock.

Information concerning the Company’s equity compensation plans is included under Item 12 of Part III of this Form 10-K.

The following table summarizes selected financial information of the Company, which has been recast to present the Fire Rescue Group as a discontinued operation, as of and for each of the five years in the period ended December 31, 2014:2015:

Management’s Discussion and Analysis of Financial Condition and Results of Operations (“MD&A”) is designed to provide information that is supplemental to, and shall be read together with, the consolidated financial statements and the accompanying notes contained in this Form 10-K. Information in MD&A is intended to assist the reader in obtaining an understanding of (i) the consolidated financial statements, (ii) the Company’s business segments and how the results of those segments impact the Company’s results of operations and financial condition as a whole and (iii) how certain accounting principles affect the Company’s consolidated financial statements.

The Company is a leading global manufacturer and supplier of (i) sewer cleaners, vacuum trucks, street sweepers and other environmental vehicles and equipment and (ii) safety, security and communication equipment and (iii) vehicle-mounted, aerial platforms for fire fighting, rescue, electric utility and industrial applications.equipment. We also are a designer and supplier of technology-based products and services for the public safety market. In addition, we sell parts and provide service, repair, equipment rentals and training as part of a comprehensive offering to our customer base. We operate twelvenine manufacturing facilities in sixfour countries around the world and provide products and integrated solutions to municipal, governmental, industrial and commercial customers in all regions of the world.

The following table summarizes our Consolidated Statements of Operations and illustrates the key financial indicators used to assess our consolidated financial results:

Net sales increased by $67.2$66.2 million, or 8%9%, for the year ended December 31, 2014 compared to the prior year, primarily driven by our Environmental Solutions Group, which reported a net sales improvement of $62.6 million, or 13%, which primarily resulted from a $41.1 million increase in sales volumes, improved pricing strategies and favorable product mix linked to higher sales to industrial customers. Vacuum truck sales increased by $22.6 million, largely resulting from increased production throughput and productivity gains within our manufacturing facilities that have resulted in improved sales volumes of hydro-excavation products. Street sweeper sales were also $21.5 million higher than the prior year, and arewere reflective of improved municipal demand. There was also improvement in both the Safety and Security Systems and Fire Rescue groups,Group, where net sales increased by $3.6 million, or 2%, and $1.0 million, or 1%, respectively..

For the year ended December 31, 2014, cost of sales increased by $39.0$33.5 million, or 6%, compared to the prior year, largely driven by an increase of $33.8 million, or 9%, within the Environmental Solutions Group associated with higher unit volumes. Cost of sales were also up year over year within our Fire Rescue Group, which reported an increase of $5.5 million, or 5%. These increases were partially offset by a $0.3 million reduction within our Safety and Security Group.

For the year ended December 31, 2014, gross profit increased by $28.2$32.7 million compared to the prior year. Gross margin for the year ended December 31, 2014 was 25.4%26.8%, up from 24.1%24.7% in the prior year. The improvement in gross margin was primarily the result of increased volumes that leveraged production capacity, favorable product mix associated with higher sales to industrial customers and productivity and facilities utilization improvements within our Environmental Solutions Group. Gross

Selling, engineering, general and administrative (“SEG&A”)&A expenses increased by $6.9$6.3 million for the year ended December 31, 2014 compared to the prior year, primarily due to a $5.1 million increase within the Environmental Solutions Group, resulting from higher employee incentive and stock-compensation expense, product liability costs and consulting expenses. In addition, SEG&A expenses at Corporate were $2.3 million higher than the prior year, largely due to increased employee incentive and stock-compensation expense. These increases were partially offset by lower expenses of $1.1 million within the Safety and Security Systems Group, primarily due to lower pension expense and staffing costs.

There were no restructuring charges in 2014.

Operating income for the year ended December 31, 2014 increased by $22.0$27.1 million, or 31%44%, when compared to the prior year. The increases were primarily attributable to improved operating leverage and increased volumes within our Environmental Solutions Group, which contributed to a $28.8 million improvement in gross margin,profit, and improved performance in our Safety and Security Systems Group.Group, where gross profit increased by $3.9 million. These increases were largely offset by increased

SEG&A expenses within Corporate and the Environmental Solutions Group, and a $5.1 million decrease in operating income within our Fire Rescue Group, primarily due to the $4.5 million reduction in gross profit.Group. Operating income for the year ended December 31, 2014 was also favorably impacted by the $0.7 million reduction in restructuring charges.charges and lower SEG&A expenses in our Safety and Security Systems Group.

Compared with the prior year, interest expense for the year ended December 31, 2014 decreased by $5.0$5.3 million, or 57%60%, primarily due to significant reductions in debt levels. For the year ended December 31, 2014, interest expense further benefited from lower interest rates on borrowings that resulted from our March 2013 debt refinancing. For further discussion, see Note 5 – Debt to the accompanying consolidated financial statements.

There were no debt settlement charges in 2014.

In the first quarter of 2013, the Company recorded $8.7 million of charges related to the termination of our prior debt facilities. The expenses included the write-off of deferred financing fees of $4.5 million and a prepayment penalty of $4.2 million.

The Company recognized income tax expense of $24.3$23.7 million for the year ended December 31, 2014, compared to an income tax benefit of $107.2$108.6 million in the prior year. The Company’s effective tax rate for the year ended December 31, 2014 was 27.8%28.4%, compared to (202.3)(247.4)% in 2013.

Income from continuing operations was $63.0$59.7 million for the year ended December 31, 2014, compared with $160.2$152.5 million in the prior year. The lower income is largely due to increased income tax expense, partially offset by improved operating income and reduced interest expense, as further explained above. Income from continuing operations for the year ended December 31, 2014, was also positively impacted by the absence of $8.7 million of debt settlement charges incurred in connection with our prior year debt refinancing.

For the year ended December 31, 2014, the Company recorded a net gain from discontinued operations and disposal of $0.7 million. The gain primarily relates to$4.0 million, which included $3.3 million of net income generated by the Fire Rescue Group, which was discontinued in 2015, as well as adjustments of estimated product liability obligations of previously discontinued businesses, resulting from updated actuarial valuations.

For the year ended December 31, 2013,2015, total orders of $686.1 million decreased by $121.3 million, or 15%, compared to the prior year, largely due to lower demand for vacuum trucks, street sweepers and sewer cleaners, which led to an $106.4 million decrease in orders within our Environmental Solutions Group. Our Safety and Security Systems Group also reported decreased orders of $14.9 million.

For the year ended December 31, 2014, total orders of $957.4$807.4 million increased by $120.6$101.4 million, or 14%, compared to the prior year, largely due to higher demand for street sweepers, vacuum trucks and sewer cleaners which led to an $85.9 million increase in orders within our Environmental Solutions Group. Our Fire Rescue and Safety and Security Systems groupsGroup also reported improved orders of $19.2 million and $15.5 million, respectively.million.

The following table summarizes the Environmental Solutions Group’s operating results as of and for the years ended December 31, 2015, 2014 2013 and 2012:2013:

The following table summarizes the Safety and Security Systems Group’s operating results as of and for the years ended December 31, 2015, 2014 2013 and 2012:2013:

Corporate operating expenses were $26.0 million, $25.3 million $22.7 million and $27.3$22.7 million for the years ended December 31, 2015, 2014 and 2013, and 2012, respectively.